A wide variety of computer systems have been used to create, edit, deliver, and store recorded digital signals, such as, music and video. Such computer systems generally include commercially-available computer program products which allow people to create music and/or videos from multiple recorded signals, edit the music and/or videos in a variety of ways including combining and changing multiple recorded signals, and store the music and/or video in some medium that allows the user to deliver the music and/or video in some fashion. Examples of such computer program products include programs, such as, ACID™, VEGAS® Video and Vegas Audio, and SIREN™ Juke Box software programs developed and sold by Sonic Foundry, Inc., of Madison, Wis. These exemplary programs are described and can be purchased on the Internet at http://www.sonicfoundry.com.
Such computer-readable recorded signals (of music and/or videos) can be stored in a variety of different computer storage formats. A wide variety of computer file formats can be used to store recorded signals, depending on the software application used and file format selected. Example file formats include the Moving Picture Experts Group Layer-3 Audio (MP3) audio file format, MICROSOFT wave (WAV) audio file format, Windows Media Audio (WMA) audio file format, QUICKTIME audio-video format, or audio video interleave (AVI) format.
Heretofore, music and/or videos have been produced using computers and other electronic devices. Therefore, such music or videos can include rhythms which repeat at very precise intervals. Disc jockeys, for example, count on the precision of such rhythms to synchronize playback and create new mixes of music. Producers of videos, as another example, utilize the effects of changing musical rhythms, volume, and other such effects to achieve a variety of results in videos. Computer systems can be particularly helpful in the synchronization and manipulation of such music and/or videos because of the capacity of computers to combine and process audio and video signals, maintain large libraries of songs and visual images, and store such creations for later delivery.
One of the challenges in matching audio and video is the need to adjust the tempo of the audio as to have it coincide with the video or other audio. For example, when a video scene changes from a slow moving pastoral scene to a series of action shots, a video producer or composer may want the style and tempo of the music to reflect this change. Arranging the music such that the downbeat (i.e., the strongest beat in a measure of music) of the musical phrase is synchronized with a change in scene can emphasize or complement the video, making for a better experience for the viewer. Nevertheless, computer programs have not heretofore provided for the adjustment of tempo to match audio and video or other audio.
Thus, there is a need to synchronize audio and video changes such that music changes with the accompanying video in a way that makes sense visually and audibly. Further, there is a need to determine the tempo of a portion of music such that one phrase ends and another begins at a frame of video or portion of audio that the producer or composer wants to emphasize or complement. Even further, there is a need to automate the process of calculating and creating a musical tempo map to facilitate the synchronization of audio to video or other audio.
The teachings hereinbelow extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned needs.